A dolphin spotted in San Francisco Bay (CBS)A dolphin spotted in San Francisco Bay (CBS)

SOUTH SAN FRANCISCO (CBS 5) – A bottlenose dolphin has been spotted swimming in circles in a slew just north of San Francisco International Airport.

CBS 5’s Ken Bastida confirms that the animal is not trapped, and could leave the wide slough if he wants. Experts from the Marine Mammal Center in Sausalito came down Wednesday and said the behavior is not uncommon.

“He was making small little circles, maybe he was hunting,” said Ben Calvert of the Marine Mammal Center. “Now he’s making big laps…slowly inching out towards the bay.”

Calvert said the bottlenose dolphins have distinctive scars and that they have seen this one before in the Monterey Bay.

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)